Study on mechanical properties and hydration process of super early age UHPC
Ultra-high performance concrete (UHPC)has excellent mechanical properties and durability,its early hydration degree and shrinkage increase rapidly,which suggests that the cracking sensitivity of UHPC is high at early ages.Based on mechanical and thermos-gravimetric tests,this study analyses the time-varying laws of tensile and compressive strength,tensile strain,elastic modulus and hydration process of UHPC at super early ages.The results show that the compressive strength and tensile strength of UHPC develop rapidly at the super early age and the strength can reach more than 45％ of the 28-day strength at one day.The tensile strain of UHPC first decreases and then increases with time and finally tends to be stable.The tensile strains of UHPC are about 77×10-6 to 92×10-6 at the super early age and 135×10-6 to 163× 10-6 at the mature age.The development of elastic modulus and compressive strength of UHPC at the super early age is similar,and the relationship between the elastic modulus and compressive strength of UHPC follows the law of power function,and the tensile to compressive ratio is about 0.06.The super early hydration process of UHPC develops rapidly and the hydration degree of UHPC reaches 20％ to 30％ at one day while the low water to binder ratio leads to the low hydration degree of UHPC,which is only 40％ to 50％ at 28 days.
UHPCsuper early agemechanical propertytensile strainprocess of hydration
万方数据
维普
